1. Field of the Invention
The present invention relates to an yttrium oxide material, a member for a semiconductor-manufacturing apparatus, and a method for producing the yttrium oxide material.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2006-69843 (hereinafter referred to as Patent Document 1) discloses an yttrium oxide material for ceramic members for semiconductor-manufacturing apparatuses. The yttrium oxide material contains yttrium oxide and 2% to 30% by weight silicon carbide with a particle size of 0.03 to 5 μm, is electrically conductive, and has corrosion resistance and durability to halogen plasma gas.
The yttrium oxide material disclosed in Patent Document 1 contains such silicon carbide so as to be electrically conductive and so as to have corrosion resistance and durability during semiconductor manufacture; however, properties thereof are insufficient. Therefore, there has been a need for yttrium oxide materials with improved properties such as high mechanical strength.
The present invention has been made to cope with such a need. It is a principal object of the present invention to provide an yttrium oxide material with increased mechanical strength, a member for a semiconductor-manufacturing apparatus, and a method for producing the yttrium oxide material.
The inventors have conducted intensive studies to achieve the object and have found that the presence of inorganic particles in yttrium oxide grains and at boundaries therebetween is effective in increasing mechanical strength. This has led to the completion of the present invention.